The present invention relates to an apparatus for generating fine bubbles having positive charges and a water treatment apparatus that sterilizes and disinfects treated water using the same.
In general, fine bubbles having a very small size of 1/100 mm to 1/1000 mm can be used as eco-friendly energy sources based only on water and air.
Unlike general bubbles, fine bubbles have a very small size of not more than 1 μm and microscopic bubbles have a size of not more than 50 μm.
As known in the art, when such fine bubbles having an ivory color contract and extinguish in water through continuous explosion while ascending at a very slow speed, impact waves including ultrasound waves of 40 kHz are generated and propagate at a speed of 400 km per hour together with large amounts of negative ions and instantaneous high heat, thereby providing various effects. Thus, various application techniques may be developed using such properties of fine bubbles.
Based on experimental results that fine bubbles can help blood circulation in the human body, it is recognized that hot springs using fine bubbles provide similar effects to water containing ozone, such as sterilization and activation of living things, and that fine bubbles can be applied to various fields, such as medical systems, heath facilities, food processing, agricultural water, fish farms, and the like.
Further, fine bubbles can remove various agricultural pesticides from vegetables and fruits when washing the vegetables and fruits, and can easily discharge waste from the skin of a user to maintain good skin conditions while massaging and relieving muscles of the user, enabling fatigue recovery.
Various types of fine bubble generation apparatuses for using various functions of fine bubbles are disclosed in the art.
Korean Patent No. 10-0748580 discloses a fine bubble generation apparatus, in which water filled in a water tank is introduced and discharged by a pump while a small amount of air is injected and compressed to high pressure, such that fine micrometer-scale bubbles can be generated due to friction while the air is exhausted into the water tank through a nozzle having pores.
Such a conventional fine bubble generation apparatus includes a pump for pumping and circulating water in a water tank, an air supply valve for supplying air to circulation water, a compression tank, and a special micro nozzle placed at an exhaust side and having pores, through which highly compressed water passes to generate a large amount of fine bubbles when discharged.
A water treatment method of removing particles from water by injecting fine bubbles is known in the art. For example, dissolved air flotation (DAF) is a water treatment method, by which fine bubbles are generated to induce collision between fine rising bubbles and floating or depositing particles in water such that agglomerates of the bubbles and the particles can be formed and removed from a water surface. DAF is used to remove particles having low densities such as algae and flocs in water and a floatation method is used to separate ores by blowing air.
According to the theory of particle collision in water, the most important factor for removing particles by injecting fine bubbles is electrostatic characteristics and sizes of particles and the electrostatic characteristics are most important.
Most particles in water are charged with negative ions, and fine bubbles injected in a conventional water treatment method are also charged with negative ions.
Thus, in the related art, since particles charged with negative ions and bubbles charged with negative ions collide with each other, there are problems of efficiency deterioration and excessive pretreatment.
Although some examples of artificial production of fine bubbles charged with positive charges using a surface absorbent as a chemical agent for enhancing water treatment efficiency are known in the art, use of the chemical agent such as the surface absorbent can provide drawbacks, such as contamination of drinking water or natural water, safety deterioration, and increase in treatment costs.